Technical Bulletin 191 has been posted to the knowledgebase. It is titled Changing the Exchange Server name for Add2Exchange.
From the summary:
This document describes the process for changing the name of the Exchange server which Add2Exchange is using for synchronization.
This is not a server move guide (for moving Add2Exchange to another server). If you need instructions on how to move Add2Exchange to another server, see the Add2Exchange Enterprise Guide at:
http://guides.diditbetter.com/a2e-guide/server_moves.htm
The bulletin is available at:
http://support.diditbetter.com/kb/A2E_191.aspx.